Surface treatment agent comprising inorganic-organic hybrid material

ABSTRACT

A surface treatment agent, which contains:
     (A) a hydrolyzable metal alkoxide or a hydrolyzate thereof,   (B) a fluorocompound containing a perfluoroalkyl group and a functional group reactive with the hydrolyzable metal alkoxide (A), and   (C) an adhesion improvement agent,
 
can provide a film having transparency and durability while maintaining excellent soil releasability and low refractive index.

FIELD OF THE INVENTION

The present invention relates to a surface treatment agent which issoluble in an organic solvent and imparts superior soil releasabilityand water repellency. Particularly it relates to a photo-curablecomposition which can form a cured film having excellent weatherability,thermal resistance, transparency and scratch resistance under excellentphoto-curability on surfaces having various shapes, such as plastics,metals, ceramics, quartz glass, glass, silicones, oxidized silicones,woods, papers and fibers and which has preservation stability and to acured film thereof.

Thus, the thermosetting composition of the present invention, the curedfilm or cured material therefrom are suitable for a paint for metal, asizing agent such as a slate material, a hard coating of a plastic film,a hard coating of a print paper, a stain-proofing film for a floor, awall tile and a fiber, a hard coating of an optical lens, a protectivefilm of a display device, an antireflective film, a highly reflectivefilm, a selective transmission film, a coverage reinforcing material ofa fiber, a resin for an optical three-dimensional shaping, an opticallens, a semiconductor sealing material, a semiconductor insulation film,a semiconductor adhesive, an optical adhesive, a printing platematerial, an actuator, an optical fiber, a pellicle, a wavelengthdivision multiplex (WDM) transmission system, an optical communicationsystem material for noise filtering, a resist material, a printer headink water-repellent film, a flame retardant material, an optical filter,an optical filter for solar cell, an antireflective film for laser, anda photonics material such as an optical waveguide material and opticalswitching material.

RELATED ART

Recently, various developments can be seen on various display devices,associating with developments of multimedia. Among various displaydevices, the improvement of visibility in devices which are usedoutdoor, particularly mobile devices, are increasingly important, andthe easy visibility also in large display devices is required by theusers. These matters as such are technical problems.

Hitherto, as one means for improving the visibility of display devices,an antireflective film made of a low refractive index material is coatedon a substrate of the display device. As the methods of forming theantireflective film, known is a method of forming a thin film of, forexample, fluorocompound by a vapor deposition. Recently, sought is atechnology capable of forming the antireflective film in devices,particularly liquid crystal display devices, with a low cost, also inlarge display devices. However, it is difficult for the vapor depositionmethod to form a homogeneous antireflective film in high efficiency on alarge area substrate and to decrease the cost due to the necessity of avacuum apparatus.

Under these circumstances, studied is a method of forming anantireflective film by dissolving a fluoropolymer having a lowrefractive index into an organic solvent, preparing a liquidcomposition, and coating the composition on a substrate surface. Forexample, JP-A-64-1527 proposes that a fluorinated alkyl silane is coatedon substrate surface and JP-A-6-115023 proposes that a fluoropolymerhaving a specific structure is coated. In addition, JP-A-7-126552proposes a method of coating a ultraviolet light-curablefluorine-containing material and JP-A-2000-17028 proposes a method ofcoating an organic and inorganic hybrid fluoropolymer. However, thesematerials have insufficient soil releasability, low-refractive index andscratch resistance, since multiple layers of a fluorine-containingcomponent and a fluorine-free component are not possessed.

J. Applied Polymer Science, 65 (12), 2387 (1997) discloses that theprovision of a hydrophobic inorganic and organic hybrid material thinfilm on glass can impart the water repellency and the glass protection.However, this hybrid material has insufficient water repellency andantireflectivity and soil releasability.

Generally, when a person uses the display device, a finger soil, afingerprint, a sweat, a cosmetics and the like are adhered to a displayscreen. For example, when the antireflection film is formed, a soilcaused by the adhesion is easily outstanding, and said soil cannot beeasily removed. In order to prevent the soil or to easily wipe off thesoil, a soil release layer is devised to be provided on a surface of theantireflective film. For example, JP-A-64-86101 proposes anantireflective article having soil releasability and scratch resistance,wherein an antireflective film mainly made of silicon dioxide isprovided on a substrate surface and an antireflective film surface istreated with a compound containing an organic silicon substituent.JP-A-4-338901 proposes a CRT filter having soil releasability andscratch resistance wherein a terminal silanol organic polysiloxane iscoated on an antireflective film. In addition, JP-B-6-29332 proposes alow-reflection plastic having low reflectivity and soil releasabilitywherein an antireflective film comprising a mono- or di-silane compoundcontaining a polyfluoroalkyl group and a silane compound containing ahalogen atom, an alkyl group or an alkoxy group is laminated on aplastic surface.

However, the surface treatment agents formed by these conventionalmethods can give a specific soil releasability and antireflectivitywhich are not sufficient. Since the adhered soil cannot be easily wipedoff, it is necessary to use water and/or an organic solvent for theremoval. Since this wiping off can easily peel off a substanceexhibiting the soil releasability, the durability of the soilreleasability is poor. Said fluorine-containing coating materials giveinsufficient scratch resistance of the resultant coating so thatparticularly when the coating is repeatedly rubbed, the coating ispeeled off. In addition, unreacted acrylic monomers and polyfunctionalacrylic compounds are easily remains in the coating film so that thecured coating film has poor properties. In addition, if the fluorinecontent is intended to be increased, a surface active agent such as areactive emulsifier must be disadvantageously introduced into thecomposition. In order to exhibit excellent soil releasability andtransparency, and low refractive index and excellent antireflectiveproperty as well as excellent scratch resistance, a multi-layeredcoating is essential so that coating once cannot form afluorine-containing multi-layered structure, thus the preparationprocess is disadvantageously complicated.

Generally, a method of forming an antireflective film comprising a thinfilm on an optical substrate comprises forming a single layer or aplurality of layers. The method is performed in many years, and a thinfilm is generally prepared by a film formation procedure such as avacuum deposition of inorganic material.

If the number of layers in the thin film is small, it is difficult toobtain the antireflective effect for a light having a wide wavelengthrange, because the refractive index of the thin film is definitelydetermined. In order to obtain the antireflective effect over a widewavelength range, it is necessary that the refractive index of the filmis made gradient by continuously distributing the refractive index.Hitherto, a method of forming an graded refractive index distributionincludes that a plurality of thin films are formed or a porous film isformed.

Also in order to prevent the reflective index from changing depending onan incident angle, it was necessary that larger number of thin layersare laminated or porous film is formed. That is, the light amountdepending on the incident angle of light can be controlled by filmformation.

Basically, the antireflective film counteracts the reflection light byutilizing the interference of light, and it is necessary to finelycontrol the refractive index of material and the film thickness when athin film is formed. Depending on increasing the number of layers ofthin film and on making the thin film porous, disadvantageously, theproductivity is decreased, the substrate is curved and the mechanicalstrength is deteriorated.

As described in, for example, JP-A-2001-272505, there is a cop-shapedantireflective film which has fine concave and convex on an opticaldevice surface, that is, a volume ratio of the optical element side tothe air side that continuously changes. Also in J. Non-Cryst. Solid, 121(1990) 294–302, there is a cop-shaped antireflective film which has avolume ratio of the optical element side to the air side thatcontinuously changes. However, because these antireflective filmscontain no fluorine and have the concave-convex structure, the soilreleasability and the durability against mechanical strength is notsufficient.

SUMMARY of THE INVENTION

The present invention was carried out under such a background. Oneobject of the present invention is to provide a surface treatment agent,soluble in general hydrocarbons, which can continuously form a coatingfilm having excellent soil releasability and transparency and lowrefractive index and exhibiting excellent ant-reflective effect, andwhich is excellent in scratch resistance and soil releasability. Otherobject of the present invention is to provide a surface treatment agentexcellent in soil releasability and transparency as well as scratchresistance. Further object of the present invention is to provide anantireflective film having these properties.

The present invention provides a antireflective film having therefractive index continuously changing based on the its tissue, sincethe surface treatment agent contains a fluorocompound and containscompounds having different refractive indexes which are complexed in ananoscale. This antireflective film can easily exhibit the lowreflectance property over a wide wavelength range by the coating,different from a conventional cop-shaped antireflective film. Inaddition, since the film is coated on the surface with thefluorocompound, the film has, for example, no adhesion of finger printso that the soil releasability is excellent and the film is in amonolithic structure so that the film can exhibit the durability againstan external mechanical force.

The surface treatment agent of the present invention comprises:

-   (A) a hydrolyzable metal alkoxide or a hydrolyzate thereof,-   (B) a fluorocompound containing a perfluoroalkyl group and a    functional group reactive with the hydrolyzable metal alkoxide (A),    and-   (C) an adhesion improvement agent.

The present invention also provides an optical article coated with atransparent film, which has:

-   (i) a region having a continuous wavelength range of at least 100 nm    exhibiting a reflectance of at most 20% in the reflectance    characters viewed from a coating side at a 150 to 1,600 nm    wavelength range, and-   (ii) a surface free energy of the film surface of at least 6.0    mJ/m².

This optical article can be prepared by coating a surface treatmentagent comprising:

-   (A-1) a hydrolyzable metal alkoxide or a hydrolyzate thereof, and-   (B-1) an organic compound containing a fluorine atom, on the    substrate. The coating may be a plurality of times (for example,    twice to ten times) and is preferably one time (that is, one    coating).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a graph showing the presence amount of a fluorine atom indepth direction of the film measured by an X-ray photoelectronspectroscopy for the coating films obtained in Examples 7, 9 and 10 andComparative Examples 2 and 3.

FIG. 2 shows a graph showing the presence amount of a carbon atom indepth direction of the film measured by an X-ray photoelectronspectroscopy for the coating films obtained in Examples 7, 9 and 10 andComparative Examples 2 and 3.

FIG. 3 shows a graph showing the presence amount of a silicon atom indepth direction of the film measured by an X-ray photoelectronspectroscopy for the coating films obtained in Examples 7, 9 and 10 andComparative Examples 2 and 3.

FIGS. 4 and 5 show graphs showing a refractive index distribution indepth direction of the film measured by a multi-incident-typespectroscopic ellipsometer for the coating films obtained in Example 7and Comparative Example 4.

FIGS. 6 and 7 show graphs showing a reflectance of the film measured bya reflectometer for the coating films obtained in Example 7 andComparative Example 4.

DETAILED EXPLANATION OF THE INVENTION

The surface treatment agent of the present invention comprising thecomponents (A) to (C) is excellent in soil releasability andtransparency and can give a surface treatment coating and anantireflective film having excellent scratch resistance.

The component (A) is preferably a hydrolyzable metal alkoxide of thegeneral formula (1) or a hydrolyzate thereof:R¹¹ _(a)(R¹²O)_(b)M{O-MR¹¹ _(g)(OR¹²)_(h)}_(f)—R¹¹ _(d)(OR¹²)_(e)  (1)wherein each R¹¹ is an alkyl group, a methacryloxy group, acryloxygroup, a vinyl group-containing organic group, an aryl group, an aminogroup, a glycidyl group, an isocyanate group, or a carboxylgroup-containing organic group,each R¹² is an alkyl group, an alkoxyalkyl group, or an aryl group,

-   M is a metal,-   a is from 0 to 3, b is from 0 to 4, a+b is from 2 to 4, d is 1 or 0,    e is 1 or 0, d+e is 1, f is from 0 to 10, for example, from 0 to 4,    g is 0 to 3, h is 0 to 3, g+h is from 1 to 3, at least one of b, e    and h is at least 1. The carbon number of R¹¹ and R¹² may be from 1    to 18 (The carbon number may be from 6 to 18, if they contain the    aryl group).

The component (A) may be a cage-like silsesquioxane, for example, acompound of the following structure.

wherein R is an aliphatic hydrocarbon group (for example, an alkyl grouphaving 1 to 5 carbon atoms, particularly a methyl group) or an aromatichydrocarbon group (for example, a phenyl group), or a group containingan acryloyl group, a methacryloyl group or an oxetane group.

The fluorocompound (B) contains the perfluoroalkyl group and has thefunctional group reacting with the hydrolyzable metal alkoxide (A).Examples of said functional group include an alkoxysilane group, acarboxyl group, a hydroxyl group, an epoxy group, a phosphate group, ahalogenated silyl group, a sulfone group, an amino group, an isocyanategroup and a blocked isocyanate group.

The component (B) is preferably a perfluoroalkyl group-containinghydrolyzable metal alkoxide of the general formula (2):

wherein Rf is a linear or branched perfluoroalkyl group having 1 to 16carbon atoms,

-   X is an iodine atom or a hydrogen atom,-   Y is a hydrogen atom or a lower alkyl group (for example, an alkyl    group having 1 to 8 carbon atoms),-   Z is a fluorine atom or a trifluoromethyl group,-   R¹ is a hydrolyzable group, or a chlorine atom,-   R² is a hydrogen atom or a inert monovalent organic group,-   a, b, c and d are an integer of from 0 to 200,-   e is 0 or 1,-   m and n are from 0 to 2,-   p is an integer of from 1 to 10,-   M is a metal, or a reactive group selected from the group consisting    of an isocyanate group, a carboxyl group, a hydroxyl group, a    glycidyl group, a phosphate group, a sulfonate group and an amino    group, or a hydrolyzate thereof.

The hydrolyzable metal alkoxide and the like of the component (B) easilyhydrolyzes to easily react with the hydrolyzable metal alkoxide (A)

The component (C) has a surface free energy of at least 10 mJ/m², forexample, at least 15 mJ/m², particularly at least 20 mJ/m², especiallyat least 30 MJ/m². The component (C) is preferably a polymer based on afluorine-free olefin, having a number-average molecular weight of atleast 500, for example, at least 1,000. The fluorine-free olefin polymeris suitable as the agent for adhesion to the substrate, because it canexhibit excellent adhesion to a resin such as plastics.

The component (C) is preferably a polymer having a polysiloxane segmenthaving a number-average molecular weight of at least 500, for example,at least 1,000 in a side chain of a polyolefin polymer having anumber-average molecular weight of at least 500, for example, at least1,000. Because the polysiloxane segment can improve the scratchresistance, it is suitable as a sliding agent.

The surface treatment agent of the present invention preferably contains(D) a fluoropolymer in addition to the components (A) to (C). Thefluoropolymer (D) preferably has a group reacting with the component(A), for example, an alkoxysilane group, a carboxyl group, a hydroxylgroup, an amino group, a glycidyl group, an isocyanate group and ablocked isocyanate group.

Since the fluoropolymer (D) can exhibit lower refractive index and moreexcellent antireflective property and can easily dissolve in a commonhydrocarbon solvent even in a high concentration, it is not necessary tointroduce a surfactant such as a reactive emulsifier into the surfacetreatment composition.

The fluoropolymer (D) is preferably a polymer having a number-averagemolecular weight of at least 500, of the general formula (3):-(M)_(x)-(N)_(y)—wherein x and y are from 1 to 500,the structural unit M is derived from a fluorine-containing ethylenicmonomer of the formula (M):

(in which, X¹ and X² are, the same or different, H or F,

-   X³ is H, F, CH₃ or CF₃,-   X⁴ and X⁵ are, the same or different, H, F or CH₃,-   Rf¹ is an organic group wherein 1 to 3 y³ groups (Y³ is a hydroxyl    group, a glycidyl group, an amino group, an alkoxy group, a carboxyl    group, an isocyanate group, or C₁–C₁₀ monovalent organic group    having at least one of these reactive groups) are bonded to a C₁–C₄₀    fluorine-containing alkyl group or a C₂–C₁₀₀ fluorine-containing    alkyl group having an ether linkage,-   a is an integer of from 0 to 3,-   b and c are, the same or different, 0 or 1,    the structural unit N is a structural unit obtained by reacting (for    example, esterifying) an unsaturated carboxylic acid of the    formula (A) or a derivative thereof:

(in which R¹ is a divalent organic group having 1 to 7 carbon atoms,which may be substituted with a fluorine atom,

-   X⁶ is H, F, CH₃ or CF₃,-   X⁷ and X⁸ are, the same or different, H or F,-   f is 0 or 1)    with the y³ group in the Rf¹ group of the ethylenic monomer giving    the structural unit M.

Preferably, the polymer of the general formula (3) is preferably afluoropolymer which contains 0.1 to 99.9% by mol of the structural unitM and 0.1 to 99.9% by mol of structural unit N, and which has anumber-average molecular weight of 500 to 1,000,000.

<Hydrolyzable Metal Alkoxide (A)>

Preferably, the surface treatment agent of the present inventioncontains the hydrolyzable metal alkoxide (A) of the general formula (1),and the component (A) contains at least one alkoxy group.

The component (A) may be a compound of the general formula (1):R¹¹ _(a)(R¹²O)_(b)M{O-MR¹¹ _(g)(OR¹²)_(h)}_(f)—R¹¹ _(d)(OR¹²)_(e)  (1)wherein each R¹¹ is an alkyl group, a methacryloxy group, acryloxygroup, a vinyl group-containing organic group, an aryl group, an aminogroup, a glycidyl group, an isocyanate group, or a carboxylgroup-containing organic group,each R¹² is an alkyl group, an alkoxyalkyl group, or an aryl group,

-   M is a metal,-   a is from 0 to 3, b is from 0 to 4, a+b is from 2 to 4, d is 1 or 0,    e is 1 or 0, d+e is 1, f is from 0 to 10, for example, from 0 to 4,    g is 0 to 3, h is 0 to 3, g+h is from 1 to 3, at least one of b, e    and h is at least 1.

The hydrolyzable metal alkoxide (A) may be, for example, a compound ofthe general formula:(R¹¹)_(n)M(OR¹²)_(m)wherein each of R¹¹ is an alkyl group, a methacryloxy group, an acryloxygroup, a vinyl group-containing organic group, an aryl group, an aminogroup, a glycidyl group, an isocyanate group, or a carboxylgroup-containing organic group,each of R¹² is an alkyl group, an alkoxyalkyl group, or an aryl group,

-   M is a metal,-   m is from 2 to 5, particularly 3 or 4,-   n is from 0 to 2, particularly 0 or 1,-   m+n is from 3 to 5, particularly 4.

The number of the alkoxy groups in the hydrolyzable metal alkoxide (A)may be from 1 to 12, for example, from 1 to 4.

The number of carbon atoms in the alkyl group (R¹¹ and R¹²) is, forexample, from 1 to 6. The number of carbon atoms in the aryl groups is,for example, from 6 to 18. The number of carbon atoms in the vinylgroup-containing organic group and the glycidyl group-containing organicgroup is, for example, from 2 to 6. Examples of the vinylgroup-containing organic group include a vinyl group. Examples of theglycidyl group-containing organic group include an epoxy group. In thealkoxyalkyl group, the carbon number of the alkoxy group is, forexample, from 1 to 6, and the carbon number of the alkyl group is, forexample, from 1 to 6.

Examples of M (metal) are silicon (Si), titanium (Ti), aluminum (Al),zirconium (Zr), tin (Sn), iron (Fe), sodium (Na), magnesium (Mg),phosphorus (P), sulfur (S), potassium (K), calcium (Ca), scandium (Sc),vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni),copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), arsenic (As),selenium (Se), rubidium (Rb), strontium (Sr), yttrium (Y), niobium (Nb),molybdenum (Mo), cadmium (Cd), indium (In), antimony (Sb), tellurium(Te), cesium (Cs), barium (Ba), lanthanum (La), hafnium (Hf), tantalum(Ta), tungsten (W), mercury (Hg), thallium (Tl), lead (Pb), bismuth(Bi), lithium (Li), beryllium (Be), boron (B), cerium (Ce), praseodymium(Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu),gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium(Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu).

Examples of the hydrolyzable metal alkoxide (A) are as follows:

-   tetraethoxysilane [Si(OCH₂CH₃)₄] (tetrafunctional)-   methyltriethoxysilane [CH₃Si(OCH₂CH₃)₃] (trifunctional)-   dimethyldiethoxysilane [(CH₃)₂Si(OCH₂CH₃)₂] (difunctional)-   trimethylethoxysilane [(CH₃)₃SiOCH₂CH₃] (monofunctional)    ethoxysiloxane oligomer-   [(CH₃CH₂O)₃Si—{O—Si(OCH₂CH₃)₂}_(n)—(OCH₂CH₃)]-   (n=1 to 4)(functionality of 6 to 12).

In addition, examples include

isocyanatopropyltriethoxysilane [OCNC₃H₆Si(OCH₂CH₃)₃]

glycidylpropyltriethoxysilane [CH₂OCHC₃H₆Si(OCH₂CH₃)₃]

aminopropyltriethoxysilane [NH₃C₃H₆Si(OCH₂CH₃)₃][NH₂C₃H₆Si(OCH₂CH₃)₃]

compounds of formulas:

wherein R⁴, R⁵, R⁶ and R⁷ are, the same or different, a hydrogen atom oran alkyl group having 1 to 4 carbon atoms, A¹ is a direct bond or adivalent organic group,

M¹ is a metal such as Si, Ti, Al, Zn, Sn and Fe, and

n is from 1 to 3.

Specific examples thereof are as follows:

-   CH₂═CHSi(OCH₃)₃ (vinyltrimethoxysilane)-   CH₂═CHSi(OCH₂CH₃)₃ (vinyltriethoxysilane)

-   (3-methacryloxypropyltrimethoxysilane)

-   (3-methacryloxypropyltriethoxysilane)

-   (N-[2-(vinylbenzylamino)ethyl]-3-aminopropyltrimethoxy-silane    hydrochloride)

Specific examples of the alkoxy titanium group-containing monomerinclude the following:

(titanium methacrylate triisopropoxide)<Perfluoro Group-Containing Fluorocompound (B)>

The surface treatment agent of the present invention may contain thefollowing perfluoro group-containing fluorocompound (B) having thefunctional group reacting with the hydrolyzable metal alkoxide (A). Thefluorocompound (B) may be, for example, a compound of the generalformula (2):

wherein Rf is a linear or branched perfluoroalkyl group having 1 to 16carbon atoms,

-   X is an iodine atom or hydrogen atom,-   Y is a hydrogen atom or a lower alkyl group,-   Z is a fluorine atom or a trifluoromethyl group,-   R¹ is a hydrolyzable group, or a chlorine atom,-   R² is a hydrogen atom or a inert monovalent group,-   a, b, c and d are an integer of from 0 to 200,-   e is 0 or 1,-   m and n is from 0 to 2,-   p is an integer of from 1 to 10,-   M is a metal, or a reactive group selected from the group consisting    of an isocyanate group, a carboxyl group, a hydroxyl group, a    glycidyl group, a phosphate group, an amino group and a sulfonate    group.

Among them, the Rf group in the general formula (2) is usually a linearor branched perfluoroalkyl group having 1 to 16 carbon atoms,preferably, a CF₃ group, a C₂F₅ group or a C₃F₇ group. The lower alkylgroup in Y is usually one having 1 to 5 carbon atoms. The hydrolyzableR¹ group is preferably a halogen atom such as a chlorine atom, a bromineatom and a iodine atom, a R³O group, a R³COO group, a (R⁴)₂C═C(R³)COgroup, a (R³)₂C═NO group, a R⁵C═NO group, a (R⁴)₂N group, and a R³CONR⁴group (wherein R³ is an aliphatic hydrocarbon group usually having 1 to10 carbon atoms such as an alkyl group or an aromatic hydrocarbon groupusually having 6 to 20 carbon atoms such as a phenyl group, R⁴ is ahydrogen atom or a lower aliphatic hydrocarbon group usually having 1 to5 carbon atoms such as an alkyl group, R⁵ is a divalent aliphatichydrocarbon group usually having 3 to 6 carbon atoms such as analkylidene group.).

R¹ is more preferably a chlorine atom, a CH₃O group, a C₂H₅O group. R₂is a hydrogen atom or a inert monovalent organic group, preferably amonovalent hydrocarbon group usually having 1 to 4 carbon atoms such asan alkyl group. a, b, c and d are an integer of from 0 to 200,preferably an integer of from 1 to 50. m and n are an integer of from 0to 2, preferably 0. p is 1 or an integer of at least 2, preferably aninteger of from 1 to 10, more preferably an integer of from 1 to 5. Thefluorocompound (B) preferably has a number-average molecular weight offrom 5×10² to 1×10⁵, more preferably from 1×10³ to 1×10⁴.

Examples of the silane compound of the general formula (2) include thefollowing:

The preferable structure of the silane compound includes a compoundwherein Rf is a C₃F₇ group, a is an integer from 1 to 50, b, c and d are0, e is 1, Z is a fluorine atom, n is 0, that is, a compound of thefollowing formula:

wherein Y, m, R¹ and p are the same as above, and q is an integer offrom 1 to 50.

Examples of the perfluoro group-containing fluorocompound (B) are asfollows:

-   2-perfluorooctylethyltriethoxysilane    [CF₃CF₂(CF₂CF₂)₃CH₂CH₂—Si(OCH₂CH₃)₃],-   2-perfluorodecylethyltriethoxysilane    [CF₃CF₂(CF₂CF₂)₄CH₂CH₂—Si(OCH₂CH₃)₃],-   2-perfluorododecylethyltriethoxysilane    [CF₃CF₂(CF₂CF₂)₅CH₂CH₂—Si(OCH₂CH₃)₃],-   2-perfluorotetradecylethyltriethoxysilane    [CF₃CF₂(CF₂CF₂)₆CH₂CH₂—Si(OCH₂CH₃)₃],-   2-perfluorooctylethanol [CF₃CF₂(CF₂CF₂)₃CH₂CH₂OH],-   2-perfluorodecylethanol [CF₃CF₂(CF₂CF₂)₄CH₂CH₂OH],-   2-perfluorododecylethanol [CF₃CF₂(CF₂CF₂)₅CH₂CH₂OH],-   2-perfluorotetradecylethanol [CF₃CF₂(CF₂CF₂)₆CH₂CH₂OH],-   2-perfluorooctylethyltrichlorosilane [CF₃CF₂(CF₂CF₂)₃CH₂CH₂—SiCl₃],-   2-perfluorodecylethyltrichlorosilane [CF₃CF₂(CF₂CF₂)₄CH₂CH₂—SiCl₃],-   2-perfluorododecylethyltrichlorosilane    [CF₃CF₂(CF₂CF₂)₅CH₂CH₂—SiCl₃],-   2-perfluorotetradecylethyltrichlorosilane    [CF₃CF₂(CF₂CF₂)₆CH₂CH₂—SiCl₃],-   3-perfluorooctyl-1,2-epoxypropane [CF₃CF₂(CF₂CF₂)₃-Gly],-   3-perfluorodecyl-1,2-epoxypropane [CF₃CF₂(CF₂CF₂)₄-Gly],-   3-perfluorododecyl-1,2-epoxypropane [CF₃CF₂(CF₂CF₂)₅-Gly],-   3-perfluorotetradecyl-1,2-epoxypropane [CF₃CF₂(CF₂CF₂)₆-Gly],

(Gly is a glycidyl group.)

-   2-perfluorooctylethyl phosphate    [CF₃CF₂(CF₂CF₂)₃—CH₂CH₂O}_(m)—PO—(OH)_(3-m)],-   2-perfluorodecylethyl phosphate    [CF₃CF₂(CF₂CF₂)₄—CH₂CH₂O}_(m)—PO—(OH)_(3-m)],-   2-perfluorododecylethyl phosphate    [CF₃CF₂(CF₂CF₂)₅—CH₂CH₂O}_(m)—PO—(OH)_(3-m)],-   2-perfluorotetradecylethyl phosphate    [CF₃CF₂(CF₂CF₂)₆—CH₂CH₂O}_(m)—PO—(OH)_(3-m)],

(m=1 to 3)

The amount of the perfluoro group-containing fluorocompound (B) may befrom 0.1 to 300 parts by weight, for example, from 50 to 200 parts byweight, based on 100 parts by weight of the hydrolyzable metal alkoxide(A).

<Adhesion Improvement Agent (C)>

The adhesion improvement agent in the present invention preferably has asurface free energy (γ_(s)) of at least 10 mJ/m², for example, at least15 mJ/m², particularly at least 20 mJ/m². Examples of the adhesionimprovement agent (C) include polymethacrylic acid (PMAA) (molecularweight: 55,000); γ_(s)=71.0 mJ/m², a methylmethacrylate/methacryloxypropyltrimethoxysilane copolymer(P(MMA-TMSM)=9/1 molar ratio) (molecular weight: 100,000); γ_(s)=37.6mJ/m². Preferably, the adhesion improvement agent (C) is a fluorine-freeolefin polymer having a number-average molecular weight of at least 500,for example, at least 1,000. The fluorine-free olefin polymer can beobtained by reacting (a) a monomer having a carbon-carbon double bondand a metal alkoxide group (hereinafter referred to as “component (a)”)with (b) other monomer copolymerizable with the component (a)(hereinafter referred to as “component (b)”). The fluorine-free polymermay be a homopolymer of the monomer (a), a homopolymer of the monomer(b), or a copolymer between the monomers (a) and (b). The fluorine-freeolefin polymer may be a mixture of the polymer of the monomer (a) andthe polymer of the monomer (b).

The component (a) may be a compound of the general formula:

wherein R⁴, R⁵, R⁶ and R⁷ are, the same or different, a hydrogen atom oran alkyl group having 1 to 4 carbon atoms,

-   A¹ is a direct bond or a divalent organic group,-   M¹ is a metal such as Si, Ti, Al, Zn, Sn and Fe, and-   n is from 1 to 3.

Specific examples of the component (a) include an alkoxysilylgroup-containing monomer and an alkoxy titanium group-containingmonomer.

Examples of the alkoxysilyl group-containing monomer include, forexample, the following:

-   CH₂═CHSi(OCH₃)₃ (vinyltrimethoxysilane)-   CH₂═CHSi(OCH₂CH₃)₃ (vinyltriethoxysilane)

-   (3-methacryloxypropyltrimethoxysilane)

-   (3-methacryloxypropyltriethoxysilane)

-   (N-[2-(vinylbenzylamino)ethyl]-3-aminopropyltrimethoxy-silane    dihydrochloride).

Specific examples of the component (b) copolymerizable with thecomponent (a) include the following:

-   (1) alkyl vinyl ethers or cycloalkyl vinyl ethers such as methyl    vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl    vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl    vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl    vinyl ether, n-dodecyl vinyl ether, lauryl vinyl ether, cetyl vinyl    ether, 2-ethyl hexyl vinyl ether, ethyleneglycolbutyl vinyl ether,    diethyleneglycol monovinyl ether, triethyleneglycol methyl vinyl    ether and cyclohexyl vinyl ether;-   (2) vinyl esters of carboxylic acid such as vinyl acetate, vinyl    propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl    versatate, vinyl stearate and vinyl benzoate;-   (3) α-olefins such as ethylene, propylene and isobutene,-   (4) vinyl aromatic compounds such as styrene, α-methylstyrene,    o-methylstyrene, m-methylstyrene, p-methylstyrene,    p-tert-butylstyrene, diisopropenylbenzene, o-chlorostyrene,    m-chlorostyrene, p-chlorostyrene, 1,1-diphenylethylene,    p-methoxystyrene, N,N-dimethyl-p-aminostyrene,    N,N-diethyl-p-aminostyrene, vinylpyrizine and vinylimidazole;-   (5) carboxyl group-containing compounds such as (meth)acrylic acid,    crotonic acid, maleic acid, fumaric acid and itaconic acid;-   (6) alkyl(meth)acrylates such as methyl(meth)acrylate,    ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate,    butyl(meth) acrylate, isobutyl(meth)acrylate,    tert-butyl(meth)acrylate, pentyl(meth)acrylate, amyl(meth)acrylate,    isoamyl(meth)acrylate, hexyl(meth)acrylate, heptyl(meth)acrylate,    octyl(meth)acrylate, isooctyl(meth)acrylate,    2-ethylhexyl(meth)acrylate, nonyl(meth)acrylate,    decyl(meth)acrylate, isodecyl(meth)acrylate, undecyl(meth)acrylate,    dodecyl(meth)acrylate, lauryl(meth)acrylate, stearyl(meth)acrylate    and isostearyl(meth)acrylate;-   (7) hydroxyalkyl(meth)acrylates such as hydroxyethyl(meth)acrylate,    hydroxypropyl(meth)acrylate and hydroxybutyl(meth)acrylate;-   (8) phenoxyalkyl(meth)acrylates such as phenoxyethyl(meth)acrylate    and 2-hydroxy-3-phenoxypropyl(meth)acrylate;-   (9) alkoxyalkyl(meth)acrylates such as methoxyethyl(meth)acrylate,    ethoxyethyl(meth)acrylate, propoxyethyl(meth)acrylate,    butoxyethyl(meth)acrylate and methoxybutyl(meth)acrylate;-   (10) polyethyleneglycol(meth)acrylates such as polyethyleneglycol    mono(meth)acrylate, ethoxydiethylene-glycol(meth)acrylate,    methoxypolyethyleneglycol(meth)acrylate,    phenoxypolyethyleneglycol(meth)acrylate and    nonylphenoxypolyethyleneglycol(meth)acrylate;-   (11) polypropyleneglycol(meth)acrylates such as polypropyleneglycol    mono(meth)acrylate, methoxy-polypropyleneglycol(meth)acrylate,    ethoxypolypropylene-glycol(meth)acrylate and    nonylphenoxypolypropyleneglycol(meth)acrylate;-   (12) cycloalkyl(meth)acrylates such as cyclohexyl(meth)acrylate,    4-butylcyclohexyl(meth)acrylate, dicyclopentanyl(meth)acrylate,    dicyclopentenyl(meth)acrylate, dicyclopentadienyl(meth)acrylate,    bornyl(meth)acrylate, isobornyl(meth)acrylate and    tricyclodecanyl(meth)acrylate;-   (13) (meth)acrylamides such as acryloyl morpholine,    diacetone(meth)acrylamide, isobutoxymethyl(meth)acrylamide,    dimethylaminoethyl(meth)acrylamide,    diethylaminoethyl-(meth)acrylamide,    dimethylaminopropyl(meth)acrylamide, tert-octyl(meth)acrylamide,    7-amino-3,7-dimethyloctyl-(meth)acrylamide,    N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide;-   (14) unsaturated carboxylate esters such as methyl crotonate, ethyl    crotonate, propyl crotonate, butyl crotonate, methyl cinnamate,    ethyl cinnamate, propyl cinnamate, butyl cinnamate, dimethyl    itaconate, diethyl itaconate, dimethyl maleate, diethyl maleate,    dimethyl fumarate and diethyl fumarate;-   (15) unsaturated nitriles such as (meth)acrylonitrile,    α-chloroacrylonitrile, α-chloromethylacrylonitrile,    α-methoxyacrylonitrile, α-ethoxyacrylonitrile, crotonic acid    nitrile, cinnamic acid nitrile, itaconic acid dinitrile, maleic acid    dinitrile and fumaric acid dinitrile;-   (16) hydroxy group-containing vinyl ethers such as 2-hydroxyethyl    vinyl ether, 2-hydroxypropyl vinyl ether, 3-hydroxypropyl vinyl    ether, 3-hydroxybutyl vinyl ether, 4-hydroxybutyl vinyl ether,    5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether;-   (17) hydroxy group-containing allyl ethers such as 2-hydroxyethyl    allyl ether, 4-hydroxybutyl allyl ether and glycerol monoallyl    ether;-   (18) N-vinyl lactams such as N-vinyl-2-pyrrolidone and    N-vinyl-2-caprolactam;-   (19) soluble polyamide copolymers such as polyamides 6, 66, 610 and    12 copolymers.

Among the above monomeric compounds, preferably used are alkyl vinylethers, cycloalkyl vinyl ethers, vinyl carboxylate esters,methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate,isopropyl(meth)acrylate, which may be used alone or in combination.

The fluorine-free olefin polymer having the number-average molecularweight of at least 500 may be a poly-branched compound which isthree-dimensionally branched, for example, so called “dendrimer” havinghyper-branched structure having regularity. It may be a vinylgroup-containing dendrimer comprising a core portion, a split portion, abranch portion and a terminal portion wherein the terminal portioncomprises a vinyl group and an active hydrogen-containing functionalgroup other than the vinyl group, the dendrimer being obtained byreacting the polyfunctional compound (a) having at least 4 terminalfunctional groups, and at least 5 active hydrogen atoms derived fromterminal functional groups, with the vinyl group-containing compoundhaving at least one functional group capable of reacting with the activehydrogen atom so that the vinyl group is introduced in the amount of atmost 95% of all active hydrogen atoms into at least one active hydrogengroup derived from terminal functional group possessed by thepolyfunctional compound (a).

It may be, for example, the above vinyl group-containing dendrimerwherein the polyfunctional compound (a) is a polyamino dendrimer of thefollowing formula (i) or (ii). Examples of the polyamino dendrimerhaving terminal amino group include:

-   a propyleneimine dendrimer of the formulas (i) and (ii) obtained by    conducting a step of reacting butylene diamine with acrylonitrile to    reduce the terminal nitrile group into amine and repeating this step    (WO093/14147, U.S. Pat. No. 5,530,092, and JP-B-7-330631);-   an amideamine dendrimer of the following formula (iv) obtained by    conducting a step of reacting methyl acrylate to ammonia or ethylene    diamine by Michael addition and subjecting the reactants to an    ester-amide exchange reaction to introduce a secondary amino group    at the terminal, and optionally repeating this step (WO84/02705, and    JP-B-6-70132) and intermediate thereof; and-   compounds having the structures of the formulas (iii) and (v).

The amount of the component (C) is from 0.1 to 500 parts by weight, forexample, from 1 to 50 parts by weight, based on 100 parts by weight ofthe hydrolyzable metal alkoxide (A).

<Polymer Having the Number-Average Molecular Weight of at Least 500 andContaining the Polysiloxane Segment>

Specific examples of the polymer containing the polysiloxane segment inthe present invention include the following.

wherein R¹ is an alkyl group having at least one carbon atom,

-   R² is a glycidyl group, a hydroxyl group, an isocyanate group, an    alkoxy group or a carboxyl group,-   m is an integer of at least 1, and-   n is an integer of from 0 to 10.

Specific examples thereof include one wherein R² is a hydroxyl group,that is, tradenames: FM-0411 (MW=about 1,000), FM-0421 (MW=about 5,000)and FM-0425 (MW=about 10,000) manufactured by Chisso Corporation, andone wherein R² is a glycidyl group, that is, tradenames: FM-0511(MW=about 1,000), FM-0513 (MW=about 2,000), FM-0515 (MW=about 2,500) andFM-0521 (MW=about 4,000) manufactured by Chisso Corporation.

<The Fluoropolymer (D) Having the Number-Average Molecular Weight of atLeast 500>

The surface treatment agent preferably contains the fluoropolymer (D)having the number-average molecular weight of at least 500 representedby the following general formula (3), which reacts with the hydrolyzablemetal alkoxides (A) to (C). The fluoropolymer (D) is preferably of, forexample, general formula (3):-(M)_(x)-(N)_(y)—wherein x and y is, for example, from 1 to 500.

In the formula, the structural unit M is a structural unit derived froma fluorine-containing ethylenic monomer of the formula (M):

wherein X¹ and X² are, the same or different, H or F, (in which, X¹ andX² are, the same or different, H or F,

-   X³ is H, F, CH₃ or CF₃,-   X⁴ and X⁵ are, the same or different, H, F or CH₃,-   Rf¹ is an organic group wherein 1 to 3 y³ groups (y³ is a hydroxyl    group, a glycidyl group, an amino group, an alkoxy group, a carboxyl    group, an isocyanate group, or C₁–C₁₀ monovalent organic group    having at least one of these reactive groups) are bonded to a C₁–C₄₀    fluorine-containing alkyl group or a C₂–C₁₀₀ fluorine-containing    alkyl group having an ether linkage,-   a is an integer of from 0 to 3,-   b and c are, the same or different, 0 or 1.

On the other hand, the structural unit N is a structural unit obtainedby reacting (for example, esterifying) an unsaturated carboxylic acid ofthe formula (A) or a derivative thereof:

(in which R¹ is a divalent organic group having 1 to 7 carbon atoms,which may be substituted with a fluorine atom,

-   X⁶ is H, F, CH₃ or CF₃,-   X⁷ and X⁸ are, the same or different, H or F,-   f is 0 or 1),-   with the y³ group in the Rf¹ group of the ethylenic monomer giving    the structural unit M.

The carbon number of the unsaturated carboxylic acid or derivativethereof is preferably from 3 to 10. Total carbon number of y³ in M andthe unsaturated carboxylic acid or derivative thereof is preferably from3 to 10.

The amount of the component (D) is from 0.1 to 300 parts by weight, forexample, from 10 to 200 parts by weight, based on 100 parts by weight ofthe hydrolyzable metal alkoxide (A).

The fluoropolymer (D) may be a fluoropolymer which contains 0.1 to 99.9%by mol of the structural unit M and 0.1 to 99.9% by mol of structuralunit N, and which has a number-average molecular weight of 500 to1,000,000.

In the formula, the unsaturated carboxylic acid or derivative thereofwhich is reacted with the fluoropolymer containing the reactive groupsuch as the hydroxyl group possessed by the structural unit M is thecarboxylic acid having carbon-carbon double bond at the molecular endand derivative thereof, and is preferably an α,β-unsaturated carboxylicacid and derivative thereof.

Examples thereof are, for example, a carboxylic acid of the formula:

wherein R is H, CH₃, F, CF₃ or Cl,or an anhydride thereof, andan acid halide of the formula:

wherein R is the same as the above, and X is Cl or F, as well as maleicacid, maleic anhydride and monoalkyl ester of maleic acid.

Among them, the adoption of the unsaturated carboxylic halide ispreferably, since the reaction can be conducted under room temperatureand gelation of the resultant polymer can be prevented.

Specific examples of particularly preferable one include:

and the like.

A method of reacting the α,β-unsaturated carboxylic halide with thefluoropolymer containing the reactive group such as the hydroxyl grouppossessed by the structural unit M is not limited. Usually, the hydroxylgroup-containing fluoropolymer is dissolved in a solvent, theα,β-unsaturated carboxylic halide is added with stirring at atemperature of about −20° C. to 40° C. and then the reaction isconducted.

The reaction produces HCl and HF by-products, and it is desirable to adda suitable base for the purpose of trapping the by-products. Examples ofthe base include a tertiary amine such as pyridine, N,N-dimethylaniline,tetramethylurea and triethylamine, and metallic magnesium. An inhibitormay be added for the purpose of inhibiting the polymerization reactionof the α,β-unsaturated carboxylic halide and the carbon-carbon doublebond in the resultant curable fluoropolymer.

Examples of the inhibitor includes hydroquinone, t-butylhydroquinone andhydroquinone monomethyl ether.

The fluoropolymer containing the reactive group such as hydroxyl groupbefore reacting with the unsaturated carboxylic acid or derivativethereof can be obtained by (co)polymerizing the ethylenic monomer (M)containing the reactive group such as the hydroxyl group optionally withcomonomer (N) in a conventional procedure, wherein each of thesemonomers corresponds each of structural units. A radical polymerization,an anion polymerization, a cation polymerization and the like can beused as the polymerization procedure. Among them, the radicalpolymerization is preferable, because the monomers exemplified for thepurpose of obtaining the hydroxyl group-containing polymer of thepresent invention have good radical polymerizability, a quality such asa composition and a molecular weight can be easily controlled, and theradical polymerization can be easily commercialized.

The initiation of the radical polymerization is not limited, insofar asa means of radically proceeding the polymerization is used. The radicalpolymerization can be initiated by, for example, an organic or inorganicradical initiating agent, heat, light or ionizing radiation. Thepolymerization may be in solution polymerization, bulk polymerization,suspension polymerization, emulsion polymerization and the like. Themolecular weight can be controlled by a monomer concentration, apolymerization initiating agent concentration, a chain transfer agentconcentration, a temperature used in the polymerization and the like. Acomposition of the copolymer can be controlled by a composition ofmonomers charged.

The surface treatment agent of the present invention may comprise theabove-mentioned separate components (A) to (C) (and optionally thecomponent (D)) before the reaction, or may comprise the polymer ofcomponents (A) to (C) (and optionally the component (D)) after thereaction.

The surface treatment agent of the present invention may be a surfacetreatment agent which comprises:

-   (1) a polymer of the component (A) to (C) and optionally the    component (D), or    -   (A) the hydrolyzable metal alkoxide or the hydrolyzate thereof,    -   (B) the perfluoroalkyl group-containing fluorocompound having        the functional group reacting with the hydrolyzable metal        alkoxide (A),    -   (C) the adhesion improvement agent, preferably a polymer        containing a polysiloxane segment having a number-average        molecular weight of at least 500, for example, at least 1,000 in        a side chain of the adhesion improvement agent,    -   (D) optionally present, the fluoropolymer having the        number-average molecular weight of at least 500,-   (2) an active energy ray cure initiator, and-   (3) a solvent.

The active energy ray cure initiator (2) can evolve a radical, a cationand the like, and can act as a catalyst for curing (cross-linking) thehydrolyzable metal alkoxide (A) and the carbon-carbon double bond of thefluoropolymer (D), after radiating electromagnetic wave having awavelength range of at most 350 nm, that is, ultraviolet light, electronbeam, X-ray, γ-ray and the like. The cure initiator (2) can usuallyevolve the cation and radical, particularly radical, by UV light

The surface treatment agent can easily initiate the curing reaction bythe active energy ray, does not need the heating at high temperature,and can conduct the curing reaction at a relatively low temperature. Thesurface treatment agent can be advantageously applied to a substratehaving low heat resistance which can easily conduct the deformation, thedecomposition and the discoloration by the heat, for example, atransparent resin substrate.

The active energy ray cure initiator (2) in the composition of thepresent invention is selected depending on, for example, thehydrolyzable metal alkoxide (A), the type (the radical reactivity or thecationic reactivity) of the carbon-carbon double bond in thefluoropolymer (D), the type (for example, wavelength range) and theradiation strength of the used active energy ray. Generally, examples ofthe initiating agent for curing the hydrolyzable metal alkoxide (A) andthe fluoropolymer (D) having the radically reactive carbon-carbon doublebond by means of the UV-range active energy ray are as follows:

Acetophenone Type

acetophenone, chloroacetophenone, diethoxyacetophenone,hydroxyacetophenone, α-aminoacetophenone and the like

Benzoin Type

benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropylether, benzoin isobutyl ether, benzyldimethylketal and the like

Benzophenone Type

benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate,4-phenylbenzophenone, hydroxybenzophenone, hydroxypropyl-benzophenone,acrylated benzophenone, Michler's ketone and the like

Thioxanthone Type

thioxanthone, chlorothioxanthone, methylxanthone, diethylthioxanthone,dimethylthioxanthone and the like

Others

benzil, α-acyloxime ester, acyl phosphine oxide, glyoxy ester,3-ketocoumarin, 2-ethylanthraquinone, camphor quinone, anthraquinone andthe like.

A photo-initiation aid such as amines, sulfones and sulfines may beadded, if necessary.

Examples of the initiating agent for curing the hydrolyzable metalalkoxide (A) and the fluoropolymer (D) having the cationically reactivecarbon-carbon double bond are as follows:

Onium Salts

iodonium salt, sulfonium salt, phosphonium salt, diazonium salt,ammonium salt, pyridinium salt and the like

Sulfone Compounds

β-ketoester, β-sulfonyl sulfone and α-diazo compound thereof and thelike

Sulfonate Esters

alkyl sulfonate ester, haloalkyl sulfonate ester, aryl sulfonate ester,iminosulfonate and the like

Others

sulfone imide compounds, diazomethane compounds and the like.

A different embodiment of the surface treatment agent comprisinginorganic and organic hybrid material according to the present inventionis the use of a solvent. Advantageously, the surface treatment agent isdissolved or dispersed in the solvent, various substrates are coated togive a coating film which is then efficiently cured by means ofradiation such as an active energy ray to give a cured coating film.

The solvent (3) is not specifically limited, insofar as the hydrolyzablemetal alkoxide (A), the fluoropolymer (D), the active energy ray cureinitiator (2) and optionally added additives such as a curing agent, aleveling agent and a photostable agent are homogeneously dissolved ordispersed in the solvent. The solvent (3) which homogeneously dissolvesthe hydrolyzable metal alkoxide (A) and the fluoropolymer (D) isparticularly preferable. The embodiment comprising the solvent ispreferable, since a highly transparent and homogeneous film can beformed in good productivity particularly in a field which requires athin film (about 0.1 μm) as in an antireflective film application.

Examples of the solvent (3) include:

-   cellosolve solvents such as methyl cellosolve, ethyl cellosolve,    methyl cellosolve acetate and ethyl cellosolve acetate;-   ester solvents such as diethyl oxalate, ethyl pyruvate, ethyl    2-hydroxybutyrate, ethyl acetoacetate, butyl acetate, amyl acetate,    ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate,    methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl    2-hydroxyisobutyrate and ethyl 2-hydroxyisobutyrate;-   propylene glycol solvents such as propylene glycol monomethyl ether,    propylene glycol monoethyl ether, propylene glycol monobutyl ether,    propylene glycol monomethyl ether acetate, propylene glycol    monoethyl ether acetate, propylene glycol monobutyl ether acetate    and dipropylene glycol dimethyl ether;-   ketone solvents such as 2-hexanone, cyclohexanone, methyl    aminoketone and 2-heptanone;-   alcohol solvents such as methanol, ethanol, propanol, isopropanol    and butanol;-   aromatic hydrocarbons such as toluene and xylene; and mixture    solvents of at least two of these.

In order to increase the solubility of the perfluoroalkylgroup-containing fluorocompound (B) and the fluoropolymer (D), afluorine-containing solvent may be optionally used.

Examples of the fluorine-containing solvent include:

-   CH₃CCl₂F (HCFC-141b), CF₃CF₂CHCl₂/CClF₂CF₂CHClF mixture (HCFC-225),    perfluorohexane, perfluoro(2-butyltetrahydrofuran),    methoxynonafluorobutane, 1,3-bistrifluoromethylbenzene; and-   fluorine-containing alcohols such as H(CF₂CF₂)_(n)CH₂OH (n: integer    of 1 to 3), F(CF₂)_(n)CH₂OH (n: integer of 1 to 5) and (CF₃)₂CHOH,    benzotrifluoride, perfluorobenzene, perfluoro(tributyl-amine), and    ClCF₂CFClCF₂CFCl₂.

The fluorine-containing solvent can be used alone or in combination ofat least two fluorine-containing solvents or combination of at least onefluorine-containing solvent and at least one fluorine-free solvent.

Among them, the ketone solvents, the acetate ester solvents, the alcoholsolvents, the aromatic solvents and the like are preferable in view ofcoatability and productivity of the coating film.

The curable fluorine-containing surface treatment agent comprising theabove-mentioned polymer (1) containing the components (A) to (D) and theactive energy ray cure initiator (2), and the coating surface treatmentagent comprising the solvent (3) in addition to the components (1) and(2) may contains a curing agent (4), according to necessity.

The curing agent preferably one which has at least one carbon-carbonunsaturated bond and which can be polymerized by means of radical oracid. Examples of the curing agent include a radically polymerizablemonomer such as an acrylic monomer, and a cationically polymerizablemonomer such as a vinyl ether monomer. The monomer may be amonofunctional monomer having one carbon-carbon double bond or apolyfunctional monomer having at least two carbon-carbon double bonds.

The curing agent having the carbon-carbon double bond reacts in the formof a radical or cation generated from the reaction with the activeenergy ray cure initiator (2) contained in the composition of thepresent invention, and the curing agent can crosslink the polymer (1)comprising the components (A) to (D) contained in the composition of thepresent invention by means of the copolymerization between thecarbon-carbon double bond of the side chains of the polymer (1) and thecuring agent.

Examples of the monofunctional acrylic monomer which can be used as thecuring agent include acrylic acid, acrylate esters, methacrylic acid,methacrylate esters, α-fluoroacrylic acid, α-fluoroacrylate esters,maleic acid, maleic anhydride, maleate esters; and (meth)acrylate estershaving an epoxy group, a hydroxyl group, carboxyl group or the like.

Among them, the acrylate monomer having the fluoroalkyl group ispreferable in view of low refractive index of the cured material. Forexample, a compound of the general formula:

wherein X is H, CH₃ or F,

-   Rf is a fluoroalkyl group having 2 to 40 carbon atoms or a    fluoroalkyl group having 2 to 100 carbon atoms and an ether linkage,    is preferable.

Specific examples of the acrylate monomer having the fluoroalkyl groupinclude:

wherein X is a hydrogen atom, a methyl group or a fluorine atom.

As the polyfunctional acrylic monomer which can be used as the curingagent, generally known are compounds wherein a hydroxyl group in apolyhydric alcohol such as a diol, a triol and a tetraol is replacedwith an acrylate group, a methacrylate group or an α-fluoroacrylategroup. A crosslinking agent such as N,N-methylenebisacrylamide may beoptionally contained.

Specific examples of the polyfunctional acrylic monomer includecompounds wherein at least two hydroxyl groups of a polyhydric alcoholsuch as 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol,diethyleneglycol, tripropyleneglycol, neopentylglycol,trimethylolpropane, pentaerythritol and dipetaerythritol are replacedwith an acrylate group, a methacrylate group or an α-fluoroacrylategroup.

A polyfunctional acrylic monomer wherein at least two hydroxyl groups ofa polyhydric alcohol having a fluoroalkyl group or fluoroalkylene groupare replaced with an acrylate group, a methacrylate group or anα-fluoroacrylate group can be used as the curing agent, which isparticularly preferable in view of the low refractive index of the curedmaterial.

Specific examples thereof include compounds having the structure whereinat least two hydroxyl groups of fluorine-containing polyhydric alcoholsof the general formulas:

wherein Rf is a fluoroalkyl group having 1 to 40 carbon atoms,

wherein Rf is a fluoroalkyl group having 1 to 40 carbon atoms, and

-   R is H or an alkyl group having 1 to 3 carbon atoms,

-   wherein Rf′ is a fluoroalkylene group having 1 to 40 carbon atoms,    and-   R is H or an alkyl group having 1 to 3 carbon atoms, are replaced    with an acrylate group, a methacrylate group or an α-fluoroacrylate    group.

When the exemplified monofunctional and polyfunctional monomers are usedas the curing agent in the composition of the present invention,particularly α-fluoroacrylate compounds are preferable in view of goodcuring reactivity.

In the present invention, the coating film may comprise:

-   (A-1) the hydrolyzable metal alkoxide or hydrolyzate thereof, and-   (B-1) fluorine-containing organic compound.

The optical article having the coating film preferably has a continuouswavelength range of at least 100 nm exhibiting a reflectance of at least3.5%, more preferably a continuous wavelength range of at least 100 nmexhibiting a reflectance of at least 3%. The reflectivity at awavelength range of 400 to 800 nm is preferably at most 3%, particularlyat most 2.5%. The surface treatment agent preferably comprises 5 to 70mol %, based on the metal alkoxide, of the fluorine-containing compound.

Herein examples of the fluorine-containing organic compound (B-1) are asfollows:

-   (1) the perfluoro group-containing fluorocompound (B) having the    functional group reacting with the hydrolyzable metal alkoxide (A),    as well as-   (2) the fluoropolymer (D) having the number-average molecular weight    of 500 alone, and-   (3) an acrylate monomer having a fluoroalkyl group, for example, an    acrylate monomer as such, of the general formula:

-   wherein X is H, CH₃ or F,-   Rf is a fluoroalkyl group having 2 to 40 carbon atoms or a    fluoroalkyl group having an ether linkage and 2 to 40 carbon atoms,-   a homopolymer of said acrylate monomer or a combination of said    acrylate monomer and said fluoropolymer (D) (for example, a    copolymer comprising the acrylate monomer and a monomer constituting    the fluoropolymer (D)).

Specific examples of the fluoroalkyl group-containing acrylate monomerinclude:

wherein X is a hydrogen atom, a methyl group or a fluorine atom.

In the composition of the present invention, the amount of the activeenergy ray cure initiator (2) is suitably selected depending on thecontent amount of the carbon-carbon double bond in the polymer (1)comprising the components (A) to (D), the presence or absence of thecuring agent, the use amount of the curing agent, types of theinitiating agent and the active energy ray, and the radiation energyamount (strength and time of radiation). When the curing agent is notused, the amount of the active energy ray cure initiator (2) ispreferably from 0.01 to 30 parts by weight, more preferably from 0.05 to20 parts by weight, most preferably 0.1 to 10 parts by weight, based on100 parts by weight of the polymer (1) comprising the components (A) to(D).

Particularly, the amount is from 0.05 to 50% by mol, more preferablyform 0.1 to 20% by mol, most preferably from 0.5 to 10% by mol, based onthe content (molar amount) of the carbon-carbon double bond contained inthe polymer (1) comprising the components (A) to (D)

When the curing agent is used, the amount is from 0.05 to 50% by mol,more preferably form 0.1 to 20% by mol, most preferably from 0.5 to 10%by mol, based on total molar number of the content (molar amount) of thecarbon-carbon double bond contained in the polymer (1) comprising thecomponents (A) to (D) and molar number of the carbon-carbon unsaturatedbond contained in the curing agent.

The amount of the solvent (3) in the coating fluororesin composition ofthe present invention is suitably selected depending on the type of thesolid to be dissolved, the presence or absence and amount of the curingagent, the type of the substrate to be coated, and target filmthickness. The amount of the solvent is preferably so that total solidconcentration of the surface treatment agent is from 0.5 to 70% byweight, more preferably from 1 to 50% by weight.

The surface treatment agent of the present invention may contain variousadditives depending on the necessity in addition to the above-mentionedcompounds.

Examples of the additives include a leveling agent, a viscosity controlagent, a photostable agent, a moisture absorption agent, a pigment, adye and a reinforcing agent.

The surface treatment agent of the present invention may contain fineparticles of inorganic compound for the purpose of increasing thehardness of the cured material.

The fine particles of inorganic compound are not limited and preferablyhave a refractive index of at most 1.5. Specific examples thereof aredesirably fine particles of magnesium fluoride (refractive index: 1.38),silicon oxide (refractive index: 1.46), aluminum fluoride (refractiveindex: 1.33 to 1.39), calcium fluoride (refractive index: 1.44), lithiumfluoride (refractive index: 1.36 to 1.37), sodium fluoride (refractiveindex: 1.32 to 1.34), thorium fluoride (refractive index: 1.45 to 1.50).Electrically conductive or semiconductive particles of CuS, CdS, Ag andthe like are also desirable. The particle size is desirably sufficientlysmall in comparison with the wavelength of visible light, in order thatthe transparency of a low refractive index material is maintained. Theparticle size is preferably at most 100 nm, particularly at most 50 nm.

When using the fine particles of inorganic compound, they are desirablyused in the form of an organic sol which previously disperses the fineparticles into an organic dispersing medium for the purpose of notdeteriorating the dispersion stability in the composition, the adhesionin the refractive index material and the like. In order that thedispersion stability in the composition, the adhesion in the refractiveindex material and the like are improved, the surfaces of the fineparticles of inorganic compound can be previously modified by means ofvarious coupling agents. Examples of the coupling agent include anorganically substituted silicon compound; an alkoxide of a metal such asaluminum, titanium, zirconium, antimony and a mixture thereof; a salt oforganic acid; a coordination compound bonded to a coordinative compound.

The surface treatment agent of the present invention may be one whereinthe polymer (1) comprising the components (A) to (D), or the additivesare dispersed or dissolved in the solvent (3). A homogeneous solution ispreferable in view of the formation of a homogeneous thin film and thefilm formation at low temperature.

A conventional coating method can be adopted as the coating method,insofar as the film thickness can be controlled.

Examples of the coating method include a roll coating method, a gravurecoating method, a microgravure coating method, a flow coating method, abar coating method, a spray coating method, a die coating method, a spincoating method and a dip coating method. The coating method can beselected with considering the type and shape of the substrate, theproductivity of film and the controllability of the film thickness.

The surface treatment agent comprising the polymer (1) comprising thecomponents (A) to (D) and the active energy ray cure initiator (2), andthe coating film obtained by coating the surface treatment agent of thepresent invention on the substrate by, for example, the above-mentionedmethod, and drying the surface treatment agent, can be photo-cured byirradiating an active energy ray such as ultraviolet light, electronbeam and radiation.

When photo-cured, the carbon-carbon double bond in the polymer (1)comprising the components (A) to (D) polymerizes between the moleculesso that the carbon-carbon double bonds in the polymer decreases ordisappears. Thus, the coating film has the increased hardness, theimproved mechanical strength, and the improved abrasion resistance andscratch resistance. In addition, the coating film becomes insoluble in asolvent which dissolves the uncured coating film and becomes insolublein a large number of various other solvents.

Preferable film thickness of the surface treatment agent to be coated onvarious substrates is varied depending on the refractive index of thefilm and the refractive index of the substrate, and may be from 0.03 to0.5 μm, preferably from 0.07 to 0.2 μm, more preferably from 0.08 to0.12 μm. If the film thickness is too small, the decrease of reflectancecaused by light interference of visible light is insufficient. If thefilm thickness is too large, the reflectance is dependent on generallyonly the reflection at interface between air and the film so that thedecrease of reflectance caused by light interference of visible lighttends to be insufficient. The suitable film thickness is selected sothat the wavelength exhibiting a minimum value of reflectance of thearticle having the antireflective film is usually from 420 to 720 nm,preferably from 520 to 620 nm.

The antireflectively treated article wherein the surface treatment agentis applied to the substrate is explained hereinafter.

The type of article provided with the antireflective film of the presentinvention, that is, the substrate is not specifically limited. Examplesof the substrate include an inorganic material such as glass, quartzglass, silicon, silicon oxide, stone, concrete and tile; a syntheticresin such as a vinyl chloride resin, polyethylene terephthalate, acellulose resin such as triacetyl cellulose, a polycarbonate resin, apolyolefin resin, an acryl resin, a phenol resin, a xylene resin, a urearesin, a melamine resin, a diallyl phthalate resin, a furan resin, anamino resin, an alkyd resin, a urethane resin, a vinyl ester resin and apolyimide resin; a metal such as iron, aluminum and copper; wood, paper,print, photographic paper, and painting. The antireflective film isprovided on the portions other than specific portions of the article sothat the shape of the specific portions are floated by means ofreflective light to improve the decorativeness of the article.

A transparent resin substrate such as an acrylic resin, a polycarbonateresin, a cellulose resin, polyethylene terephthalate and polyolefinresin is preferably used as the substrate to effectively exhibit theantireflectivity effect. The antireflective film is preferably providedalso on an antiglaring (AG) substrate having an uneven resin surfacemade of these resins, whereby effectively exhibiting theantireflectivity effect.

The present invention is effective when it is applied to the followingarticles:

-   an optical part such as a prism, a lens sheet, a polarizing plate,    an optical filter, a lenchcular lens, a fresnel lens,-   a screen of a rear projection-type display, an optical fiber and an    optical coupler;-   a transparent protective plate such as glass of a show window, glass    of a show case, a cover for advertisement, and a cover for a    photostand;-   a protective plate for a CRT, a liquid crystal display, a plasma    display, a rear projection-type display and the like;-   a photorecording medium such as a photomagnetic disc, a read only    type photodisc, e.g., CD, LD and DVD, a phase transfer photodisc    such as PD, and hologram recording medium;-   a photolithography-related member during semiconductor production    such as a photoresist, a photomask, a pellicle, a reticule;-   a protective cover for a illuminator such a halogen lamp, a    fluorescent lamp and incandescence lamp; and-   a sheet or film which is adhered to the above-mentioned articles.

The antireflective film of the present invention can be formed bycoating the solution of copolymer (1) comprising the components (A) to(D) directly on the substrate, photo-irradiating the coating to give thecured coating film having the thickness of about 0.1 to 0.5 μm. At leastone layer is provided as an undercoat on the substrate, and theantireflective film can be formed as a topcoat on the undercoat.

The effects of the undercoat roughly classified into three effects: toincrease the scratch resistance of the topcoat, to protect the substrateand to increase the antireflectivity effect by adding a layer having ahigher refractive index than the substrate. The increase of the scratchresistance of the topcoat can be achieved by a self-repairing undercoatas exemplified in JP-A-7-168005. The protection of the substrate can beachieved by using a paint which is generally called as a hardcoat. Asthe hardcoat, exemplified are a curable-type acrylic resin and epoxyresin, a cured material of a silicon alkoxide compound, and a curedmaterial of a metal alkoxide compound. All of these can be thermallycured. For the acryl resin and the epoxy resin, a photonic (ultravioletlight) curing method is preferably in view of the productivity.

Static electricity is easily collected on the surface in the CRT and theplasma display because of apparatus characteristics. Accordingly, anadditive for imparting the electrical conductivity to the undercoatand/or topcoat layer is preferably mixed. Examples of the additive are apolymer containing an ionic group such as —COO—, —NH₂, —NH₃ ⁺,—NR¹¹R¹²R¹³ (wherein R¹¹, R¹² and R¹³ are, for example, a methyl group,an ethyl group, a n-propyl group and a n-butyl group) and —SO₃—, asilicone compound, an inorganic electrolyte and a metal fine particle(for example, NaF, CaF₂, Ag, Cu and Au).

For the purpose of preventing the adhesion of dust, an antistatic agentis preferably added to the undercoat layer and/or topcoat layer of theantireflective film. Examples of the additive are a fine particle ofmetal oxide, a fluoroalkoxysilane and a surfactant (e.g., anionic,cationic, amphoteric and nonionic), in addition to the above-mentionedadditive of imparting the electric conductivity.

The antistatic agent added to the undercoat is preferably a fineparticle of metal oxide, for example, tin oxide doped with antimony(ATO) and tin oxide containing indium (ITO), since the effects continuefor long time, the effects are not easily influenced by moisture, theantistatic effects are high, the transparency and the refractive indexare high so that the refractive index of the substrate can becontrolled, whereby increasing the antireflective effects. The AMO ispreferable in view of the transparency, and the ITO is preferable inview of the antistatic effects and the electric conductivity. Even ifthe antistatic effects are not necessary, the antireflective effects areincreased by the use of these additives, since the refractive index canbe easily controlled.

Since the ATO and ITO easily scatter and absorb the light, the thicknessof the undercoat is preferably in about submicron in order that thetransmission of the light is not prevented. The thickness thereof isdepending on the refractive index of the surface treatment agent and ispreferably from 0.05 to 0.3 μm, in order that the wavelength dependencyof the antireflectivity effects is small and the antireflectivityeffects are increased over all wavelengths. The optimum refractive indexis also depending on the refractive index of the surface treatment agentand is preferably from 1.55 to 1.95.

The hardcoat layer can be formed by coating a solution of alkylsilaneand/or polysilazane, and then heating and curing the coating. Curedfilms of melamine crosslink and an ultraviolet light-curable acrylicpaint can be also used.

The antireflective film of the present invention has the high fluorinecontent, the low surface contact angle, the water- and oil-repellencyand soil releasability so that it has both antireflectivity and soilreleasability.

The antireflective film of the present invention has pseudo-multilayerstructure (or gradation structure) so that the film near the surface hasa larger amount of fluorine atoms, the film near the substrate has asmaller amount of fluorine atoms, and the film near the center has alarger amount of an inorganic material (particularly, inorganics derivedfrom metal alkoxide). The larger amount of organic material near thefilm center contributes to decrease of the reflectance of the film.

The method of forming the curable fluoropolymer thin film includes amethod comprising coating the dispersion of the curable fluoropolymer,drying the coating and then optionally baking the coating to give a thinfilm; and a method comprising coating the solution of the curablefluoropolymer, drying the coating and then optionally baking the coatingto give a thin film.

The solution coating is preferable, since the thin film can be easilyformed. A conventional coating method can be adopted, insofar as thefilm thickness can be sufficiently controlled. For example, adopted area roll coating method, a gravure coating method, a microgravure coatingmethod, a flow coating method, a bar coating method, a spray coatingmethod, a die coating method, a spin coating method and a dip coatingmethod. The optimum coating method is determined with considering thebalance of the productivity of the coating, the controllability of thefilm thickness and the yield. After the antireflective film is formed ona film, a sheet and the like, this may be adhered to the substrate.

PREFERRED EMBODIMENTS OF THE INVENTION

Hereinafter, the embodiments of the present invention are illustrated byExamples which do not limit the present invention limited by claims ofthe present application.

The “part” and “%” are respectively “parts by weight” and “% by weight”,unless specified otherwise.

PREPARATION EXAMPLE 1

<Preparation of Perfluoroalkyl Group-Containing Fluorocompound (B);PFPEOS>

Into a 200 mL four-necked flask equipped with a stirrer, a droppingfunnel, a condenser and a thermometer, a solution ofω-fluoropolyperfluorooxetane iodide compound (40 g) of the formula (a):C₃F₇—(OCF₂CF₂CF₂)₂₄—O(CF₂)₂I  (a)in hexafluorotetrachlorobutane (80 g) and di-t-butyl peroxide (1.5 g,1×10⁻² mol), and then the flask was sufficiently replaced with anitrogen gas. Vinyltrichlorosilane (16.1 g, 0.1 mol) was dropwise addedfrom the dropping funnel under nitrogen stream. After the completion ofthe addition, the temperature of the system was increased to 120° C. toconduct the reaction for 4 hours. After the reaction, volatiles werecompletely distilled off under vacuum to give a silane compound havingterminal iodine (38.7 g). In the same flask as the above, a solution ofsaid silane compound (34.4 g) in perfluorohexane (50 g) was charged,zinc (2.1 g, 3.2×10⁻² mol) was intensely dispersed with stirring. Thesystem was cooled over an ice-water bath, anhydrous methanol (10 g) wasdropwise added under nitrogen stream. After the dropwise addition, theice-water bath was removed off, the reaction was conduced under heatedreflux for two hours. After the reaction, insolubles were filtered off,and a lower layer was removed by a separating funnel from a liquid phasehaving two layers. The resultant solution was washed three times withanhydrous methanol, and then volatiles were completely distilled offunder vacuum to give a silane compound having a hydrogenated end (31.6g) of the formula (b):

¹H-NMR showed a wide absorption band at 1.2 to 3.0 ppm derived from eachhydrogen atom in the formula (c):

SYNTHESIS EXAMPLE 1

<Synthesis of Homopolymer of Fluorine-Containing Allyl Ether Having OHGroup>

Into a 100 mL four-necked flask equipped with a stirrer and athermometer,perfluoro(1,1,9,9-tetrahydro-2,5-bistrifluoromethyl-3,6-dioxanonenol):

(20.4 g) and a 8.0% by weight solution (21.2 g) of

in perfluorohexane were charged, the nitrogen replacement wassufficiently conducted and then the system was stirred under nitrogenstream at 20° C. for 24 hours to generate a solid having a highviscosity.

A solution of the resultant solid in diethyl ether was poured intoperfluorohexane, the separation was conducted, the separated matter wasdried under vacuum to give a colorless transparent polymer (17.6 g).

The analysis of the polymer by a ¹⁹F-NMR analysis, a ¹H-NMR analysis andan IR analysis revealed that the polymer was a fluoropolymer consistingof structural units of the above-mentioned fluorine-containing allylether and having a hydroxyl group at a side chain terminal. According toa GPC analysis using tetrahydrofuran (THF) as a solvent, thenumber-average molecular weight was 9,000 and the weight-averagemolecular weight was 22,000.

PREPARATION EXAMPLE 2

<Preparation of Adhesion Improvement Agent (C); P(MMA-TMSM)>

After a 150 mL internal volume of a stainless autoclave equipped with anelectromagnetic stirrer was sufficiently replaced with a nitrogen gas,acetone (60 g), 3-methacryloxypropyl trimethoxysilane (TMSM) (5 g),methyl methacrylate (MMA) (20 g) and dilauroyl peroxide (LPO) (0.15 g)was charged and the temperature increase was initiated. The reaction wascontinued at 55° C. for 20 hours and then the reaction was discontinued.After the reaction mixture reached the room temperature, the resultantpolymer solution was poured into methanol to precipitate the polymer.The polymer was washed with methanol and vacuum-dried at 50° C. to give21 g of an adhesion improvement agent (C); P(MMA-TMSM). According to aGPC analysis using tetrahydrofuran (THF) as a solvent, thenumber-average molecular weight was 9,000 and the weight-averagemolecular weight was 20,000.

PREPARATION EXAMPLE 3

<Preparation of Fluoropolymer (D) Having Number-Average Molecular Weightof at Least 500; FAEH>

Into a 200 mL four-necked flask equipped with a stirrer, a droppingfunnel, a condenser and a thermometer, diethyl ether (80 mL), ahomopolymer of the fluorine-containing allyl ether having OH groupprepared in Synthesis Example 1 (5.0 g) and pyridine (1.0 g) werecharged, and cooled over ice to at most 5° C.

A solution of α-fluoroacrylic fluoride: CH₂═CFCOF (1.0 g) in diethylether (20 mL) was dropwise added for about 30 minutes under nitrogenstream with stirring. After the completion of the dropwise addition, thereaction was mixture was warmed to room temperature and the stirring wascontinued for 4.0 hours.

The reacted ether solution was charged into a separation funnel; washedwith water, 2% aqueous hydrochloride, 5% aqueous NaCl, and water; anddried over anhydrous magnesium sulfate. An ether solution was separatedby filtration.

A ¹⁹F-NMR analysis of the ether solution revealed that a copolymer had aratio of —OC(═O)CF═CH₂ group-containing fluorine-containing allylether/OH group-containing fluorine-containing allyl ether=40/60 by mol.

An IR analysis of a cast film prepared by coating the solution on a NaClplate and drying at room temperature showed an absorption of acarbon-carbon double bond of 1661 cm⁻¹ and an absorption of a C═O groupof 1770 cm⁻¹.

COMPARATIVE PREPARATION EXAMPLE 1

<Preparation of Fluoropolymer; PFHBVE>

After a 150 mL internal volume of a stainless autoclave equipped with anelectromagnetic stirrer was sufficiently replaced with a nitrogen gas,acetone (60 g), ethyl vinyl ether (EVE) (5.8 g), 2-hydroxyethyl vinylether (HEVE) (3.0 g) and dilauroyl peroxide (LPO) (0.15 g) were chargedand cooled over dry ice-methanol to −40° C. The autoclave was replacedagain with a nitrogen gas to remove off oxygen in the autoclave.Hexafluoropropylene (HFP) (15.0 g) was added and the temperatureincrease was initiated. At the time that the temperature of the contentin the autoclave reached 55° C., the pressure was 4.7 kgf/cm². Then thereaction was continued at 55° C. for 20 hours. At the time that thepressure reached 2.5 kgf/cm², the autoclave was cooled with water todiscontinue the reaction. After the reaction mixture reached the roomtemperature, the unreacted monomer was released and the autoclave wasopened to give a polymer solution. The resultant polymer solution waspoured into n-hexane to precipitate the polymer. The polymer was washedwith n-hexane, vacuum-dried at 50° C. to give 12.6 g of afluorocopolymer, PFHBVE.

According to a Gel permeation chromatography of a 0.5% solution of thisfluorocopolymer, PFHBVE in tetrahydrofuran (THF), the number-averagemolecular weight of the fluorocopolymer was 39,000 in terms ofpolystyrene.

COMPARATIVE PREPARATION EXAMPLE 2

<Preparation of Fluoropolymer; P17FA>

After a 150 mL internal volume of a stainless autoclave equipped with anelectromagnetic stirrer was sufficiently replaced with a nitrogen gas,acetone (60 g), perfluorooctylethyl acrylate (17FA) (10 g) and dilauroylperoxide (LPO) (0.15 g) were charged and the temperature increase wasinitiated. The reaction was continued at 55° C. for 20 hours and thendiscontinued. After the reaction mixture reached the room temperature,the resultant polymer solution was poured into methanol to precipitatethe polymer. The polymer was washed with methanol, vacuum-dried at 50°C. to give 9.1 g of a fluorocopolymer, P17FA.

PREPARATIVE PREPARATION EXAMPLE 3

<Preparation of Fluoropolymer; αF-PHFIP>

After a 150 mL internal volume of a stainless autoclave equipped with anelectromagnetic stirrer was sufficiently replaced with a nitrogen gas,acetone (60 g), α-fluoro-hexafluoroisopropyl acrylate (αF-HFIP) (10 g)and a 8.0% by weight solution (2 g) of [H(CF₂CF₂)₃COO]₂ inperfluorohexane were charged and the reaction was continued at roomtemperature for 20 hours. The resultant polymer solution was poured intohexane to precipitate the polymer. The polymer was washed with hexane,vacuum-dried at 50° C. to give 9.1 g of a fluoropolymer, αF-PHFIP.

EXAMPLE 1

<Preparation of Coating Composition>

In a 100 mL flask equipped with a stirrer, a thermometer and a droppingfunnel, to tetraethoxysilane [Si(OCH₂CH₃)₄] (TEOS; the component (A))(manufactured by Shin-Etsu Chemical Co., Ltd.) (24.4 parts), added wereheptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane[CF₃(CF₂)₇CH₂CH₂—Si(OCH₂CH₃)₃] (PFOS; the component (B))(manufactured byShin-Etsu Chemical Co., Ltd.) (7.4 parts), pure water (22.7 g), ethanol(44 g), a catalyst (nitric acid) (0.05 g) and polymethacrylic acid(PMAA; the component (C)) (1.2 parts). The mixture was subjected tohydrolysis and polycondensation reactions at room temperature for 12hours. The resultant compounds were diluted with the reaction solvent togive a solution coating composition having an effective concentration of3%.

<Preparation of Coating Film>

The above-mentioned coating composition was coated on an untreated PETsubstrate by a spin coater at room temperature and the number ofrevolutions of 500 to 2000 rpm, and dried at room temperature for 5minutes. During the coating, the number of revolution of the spin coaterwas adjusted so that the thickness of a dried film was from 90 to 110nm.

<Light Irradiation>

After dried at room temperature, the film was irradiated withultraviolet light by a high-pressure mercury lamp at room temperatureand the intense of 3,000 mJ/cm²U.

<Optical Evaluation of Coating Film>

Measurement of Refractive Index

As the optical characteristics evaluation, a sample which was preparedby coating a solution of the above-mentioned composition in MIBK by aspin coater on a PET film to give a dried film having a thickness ofabout 0.1 μm was subjected to a refractive index (n_(d) ²⁵) measurementfor light having a wavelength of 550 nm by using an Abbe refractometerat 25° C.

Measurement of Transmittance and Reflectance

The transmittance of light having a wavelength of 400 nm to 700 nm wasmeasured on a sample of the resultant coating film by using aspectrophotometer equipped with a 60 mm integrating sphere (U-3410 type,manufactured by Hitachi, Ltd.).

The reflectance of light having a wavelength of 400 nm to 700 nm wasdetermined by positioning the sample on a visible light-ultravioletlight spectrometer equipped with an acrylic plate 50° regular reflectionunit.

Measurement of Graded Refractive Index Distribution

The graded refractive index distribution was measured on the sample ofthe resultant coating film by multi-angle spectroscopic ellipsometer(M-2000: manufactured by JA Woollam Japan). A variable anglespectroscopic ellipsometry (VASE) polarization analysis was used as ananalysis software.

<Physical Properties of Coating Film>

Measurement of Pencil Hardness

The pencil hardness was measured according to JIS K5400.

Adhesion Test

The adhesion of the coating film to the substrate was evaluated by ascratch resistance of a film sample having the above mentioned curedfilm. That is, the surface of the coating film was repeatedly rubbed 25times under a load of 1 kg/cm² by using “KIMWIPE” (manufactured by JujoKimberly, K. K.), and whether the evolution of scratches on the surfacewas present or not was visually observed. The state of no peeling of thecured film and no scratch is expressed as “⊚”, the state of shallow andlinear scratches on a part of the cured film is expressed by “◯”, thestate of scratches on whole surface of the cured film is expressed as“Δ”, and the state of peeling of the cured film on whole surface isexpressed as “X”.

Contact Angle of Water and n-hexadecane

Using a contact angle meter (CA-A type: manufactured by Kyowa KaimenKagagu K. K.), a particle of water or n-hexadecane having a diameter of1 mm was prepared on a tip of a needle at room temperature, the particlewas contacted with a substrate surface to give a liquid droplet on thesurface. An angle between the substrate surface and the droplet surfacewas measured, which was taken as the contact angle.

Soil Releasability

A line was drawn on a substrate surface by a black felt pen, and wipedoff by a cellulose non-woven fabric. The easiness of removal of line wasvisually observed. A determination criterion was as follows:

⊚: Black oily ink can be completely wiped off for one wipe.

◯: Black oily ink can be completely wiped off for at most three wipes.

Δ: A wipe-off trace slightly remains.

X: A wipe off trace is spread so that removal is impossible.

Mechanical Durability

The mechanical durability was measured by using ultra-thin film scratchtester (SCRATCH TESTER CSR-02 manufactured by Rhesca Company, Ltd.)according to JIS R-3255. The bond strength between a thin film surfaceand a substrate was visually observed by scratching by means of adiamond vibration needle.

◯: No flaw when scratched under a load of 0.1–10 mN/mm².

Δ: Slight flaw when scratched under a load of 0.1–10 mN/mm².

X: flaws spread and coating film peels off when scratched under a loadof 0.1–10 mN/mm².

Atoms Present in Coating Film

The presence amount of each of a fluorine atom, a carbon atom and asilicon atom in depth direction of the coating film was determined by aX-ray photoelectron spectrometry (ESCA)

EXAMPLES 2 to 10 and COMPARATIVE EXAMPLES 1 to 4

A coating composition and a coating film were prepared and variousphysical properties were measured in the same manner as in Example 1except that the composition was replaced with those shown in Table 1.The results are shown in Table 2.

As to the coating films prepared by Examples 7, 9 and 10 and ComparativeExamples 2 and 3, the presence amount of each of a fluorine atom, acarbon atom and a silicon atom in depth direction of the coating filmwas determined by a X-ray photoelectron spectrometry. As to the coatingfilms prepared in Example 7 and Comparative Example 4, the gradedrefractive index distribution and the reflectance were determined. Theresults are shown in FIGS. 1 to 7.

Abbreviations in the Tables have the following meanings:

Component (A)

-   TEOS: Tetraethoxysilane-   NCOTSM: Isocyanatopropyltriethoxysilane    Component (B)-   PFOS: Heptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane-   PFPEOS: Perfluoroethersilane    Component (C)-   PMAA: Polymethacrylic acid-   P(MMA-TMSM): Methyl    methacrylate/3-methacryloxypropyltrimethoxysilane copolymer-   P(MMA-TMSM)-PDMS: One end OH-modified dimethyl silicone-containing    copolymer    Component (D)-   FAEH: Fluorine-containing allyl ether copolymer    Fluoropolymer-   PFHBVE: Hexafluoropropylene/hydroxybutyl vinyl ether/ethyl vinyl    ether copolymer-   P17FA: Polyperfluorooctylethyl acrylate-   αF-PHFIP: Poly-α-fluoro-hexafluoroisopropyl acrylate

TABLE 1 Example Comp. Example 1 2 3 4 5 6 7 8 9 10 1 2 3 4 MixtureComponent (A) TEOS 24.4 24.4 24.4 24.4 24.4 24.4 22.6 22.6 22.6 22.624.7 24.7 Component NCOTSM 0.1 0.1 0.1 0.1 0.1 Component (B) PFOS 7.47.4 7.4 7.4 7.5 PFPEOS 7.4 7.4 6.9 6.9 6.9 6.9 Component (C) PMAA 1.21.1 1.1 1 P(MMA-TMSM) 1.2 1.2 1.1 1.1 1.1 1.0 P(MMA-TMSM)- 0.1 0.1 0.10.1 0.1 PDMS Component (D) FAEH 6.9 6.9 6.9 6.9 Fluoro- PFHBVE 7.4polymer P17FA 55.5 αF-PHFIP 55.5 Catalyst Cat. 0.3 0.3 0.3 0.3 0.3 0.30.3 0.3 0.3 0.3 0.3 0.3 Pure water Water 22.7 22.7 22.7 22.7 22.7 22.721.1 21.1 21.1 21.1 23 23 Solvent EtOH 44 44 44.5 Acetone 44 10 44 44 1010 10 10 44.5 44.5 HCFC225 34 31 31 31 31 44.5

TABLE 2 Example Comp. Example 1 2 3 4 5 6 7 8 9 10 1 2 3 4 RefractiveIndex 1.40 1.40 1.40 1.40 1.40 1.40 1.37 1.37 1.37 1.37 1.40 1.40 1.371.36 Pencil Hardness 2H 2H 2H 2H 2H 2H 2H 2H 2H 2H 2H 2H 4B BTransmittance 95 95 95 95 95 95 95 95 95 95 95 95 95 95 (%) Reflectance(%) 1.5 1.5 1.5 1.5 1.5 1.5 1.0 1.0 1.0 1.0 1.5 3.0 2.0 3.5 AdhesionTest ◯ ⊚ ⊚ ◯ ⊚ ⊚ ◯ ◯ ⊚ ⊚ x ◯ x x Contact Angle 105 105 105 105 105 105105 105 105 105 105 65 105 100 (Water; °) (n-Hexadecane; °) 75 75 75 7575 75 75 75 75 75 75 40 75 65 Soil releasability ◯ ◯ ◯ ⊚ ⊚ ⊚ ◯ ⊚ ◯ ⊚ ◯ x◯ ◯ Mechanical Δ ◯ ◯ Δ ◯ ◯ Δ Δ ◯ ◯ x ◯ x x durabilityEffect of Invention

The present invention provides a cured film having excellenttransparency and durability while maintaining excellent soilreleasability and low refractive index. Thus the surface treatment agentof the present invention particularly provide an optical material suchas an antireflective film, a highly reflective film and a selectivelytransmission film; an optical lens, a hardcoat of an optical lens, aprotective film of a display element, a coating reinforcing material offibers, an optically three-dimensional shaping resin, a paint for metal,a sizing agent such as a slate material, a hard coat of plastic, ahardcoat of print paper, a soil release film for a floor and a walltile, an actuator, an optical fiber, pellicle, a sealant forsemiconductor, an insulating film for semiconductor, an adhesive forsemiconductor, an optical adhesive, an print plate material, a photonicsmaterial such as a light waveguide material and a light switchingmaterial. In addition, the surface treatment agent exhibits excellentradiation curability.

The surface treatment agent of the present invention can provide anantireflective film having the improved scratch resistance withmaintaining the soil releasability and the antireflectivity effect; andan antireflective article having said antireflective film coatedthereon.

1. A surface treatment agent comprising: (A) a hydrolyzable metalalkoxide or a hydrolyzate thereof, (B) a fluorocompound containing aperfluoroalkyl group and a functional group reactive with thehydrolyzable metal alkoxide (A), (C) an adhesion improvement agent, and(D) a fluoropolymer having a number-average molecular weight of at least500, wherein a one-layer film formed from the surface treatment agenthas a graded refractive index structure, and the fluoropolymer (D) is apolymer of the general formula (3):-(M)_(x)-(N)_(y)- wherein x and y are from 1 to 500, the structural unitM is derived from a fluorine-containing ethylenic monomer and is astructural unit derived from a fluorine-containing ethylenic monomer ofthe formula (M):

(in which, X¹ and X² are, the same or different, H or F, X³ is H, F,CH₃or CF₃, X⁴ and X⁵ are, the same or different, H, F or CH₃, Rf¹ is anorganic group wherein 1 to 3 Y³ groups (Y³ is a hydroxyl group, aglycidyl group, an amino group, an alkoxy group, a carboxyl group, anisocyanate group, or a C₁–C₁₀ monovalent organic group having at leastone of these reactive groups) are bonded to a C₁–C₄₀ fluorine-containingalkyl group or a C₂–C₁₀₀ fluorine-containing alkyl group having an etherlinkage, a is an integer of from 0 to 3, and b and c are, the same ordifferent, 0 or 1), and the structural unit N is a structural unitobtained by reacting an unsaturated carboxylic acid of the formula (A):

(in which R¹ is a divalent organic group having 1 to 7 carbon atoms,which may be substituted with a fluorine atom, X⁶ is H, F, CH₃ or CF₃,X⁷ and X⁸ are, the same or different, H or F, and f is 0 or 1), or aderivative thereof, with the Y³ group in the Rf¹ group of the ethylenicmonomer giving the structural unit M.
 2. The surface treatment agentaccording to claim 1, wherein the component (A) is a hydrolyzable metalalkoxide of the general formula (1) or a hydrolyzate thereof:R¹¹ _(a)(R¹²O)_(b)M{O-MR¹¹ _(g)(OR¹²)_(h)}_(f)—R¹¹ _(d)(OR¹²)_(e)  (1 1)wherein each R¹¹ is an alkyl group, a methacryloxy group, an acryloxygroup, a vinyl group-containing organic group, an aryl group, an aminogroup, a glycidyl group, an isocyanate group, or a carboxylgroup-containing organic group, each R¹² is an alkyl group, analkoxyalkyl group, or an aryl group, M is a metal, a is from 0 to 3, bis from 0 to 4, a+b is from 2 to 4, d is 1 or 0, e is 1 or 0, d+e is 1,f is from 0 to 10, g is 0 to 3, h is 0 to 3, g+h is from 1 to 3, atleast one of b, e and h is at least
 1. 3. The surface treatment agentaccording to claim 1, wherein the component (B) is a perfluoroalkylgroup-containing fluorocompound of the general formula (2):

wherein Rf is a linear or branched perfluoroalkyl group having 1 to 16carbon atoms, X is an iodine atom or a hydrogen atom, Y is a hydrogenatom or a lower alkyl group, Z is a fluorine atom or a trifluoromethylgroup, R¹ is a hydrolyzable group, or a chlorine atom, R² is a hydrogenatom or an inert monovalent organic group, a, b, c and d are an integerof from 0 to 200, e is 0 or 1, m and n are from 0 to 2, p is an integerof from 1 to 10, and M is a metal, or a reactive group selected from thegroup consisting of an isocyanate group, a carboxyl group, a hydroxylgroup, a glycidyl group, a phosphate group, a sulfonate group and anamino group.
 4. The surface treatment agent according to claim 1,wherein the adhesion improvement agent (C) is a compound having asurface free energy of at least 10 mJ/m².
 5. The surface treatment agentaccording to claim 1, wherein the adhesion improvement agent (C) is afluorine-free olefin polymer having a number-average molecular weight ofat least
 500. 6. The surface treatment agent according to claim 1,wherein the adhesion improvement agent (C) is a polymer having apolysiloxane segment having a number-average molecular weight of atleast 500 in a side chain.
 7. The surface treatment agent according toclaim 1, wherein a coating film layer contacting with air interfaceformed from the surface treatment agent has a refractive index of atmost 1.50.
 8. The surface treatment agent according to claim 1, whichfurther contains an active energy ray cure initiator.
 9. A film obtainedby photocuring the surface treatment agent according to claim
 8. 10. Anantireflective film obtained by photocuring the surface treatment agentaccording to claim
 8. 11. An antireflectively treated article comprisinga substrate and on the substrate the antireflective film according toclaim 10, wherein the substrate is made of at least one selected fromthe group consisting of an acrylic resin, polycarbonate, polyethyleneterephthalate, triacetylcellulose and polyolefin.